Ryan Jones went 48-for-143 with nine stolen bases and a .429 OBP in 42 games last season. (Salem-Keizer Volcanoes)

Giants Minor League second baseman Ryan Jones was suspended for 50 games on Thursday after testing positive for a banned substance.

The Office of the Commissioner of Baseball said Jones has received a 50-game suspension without pay after testing positive for an amphetamine, which is considered a performance-enhancing substance in violation of the Minor League Drug Prevention and Treatment Program.

The suspension of Jones will be effective at the start of the 2014 season.

Jones, 23, was San Francisco's 13th-round pick in the 2012 Draft out of Michigan State University. He hit .227 in his first season in the Minors with Class A Short Season Salem-Keizer before returning to the Northwest League in 2013 and batting .336 with no homers and 23 RBIs in 42 games.

In college, Jones was a three-year letter-winner at Michigan State and became the highest-drafted second baseman in the history of the program. He was the first Spartan second baseman to earn All-Big Ten honors three times, finished his career ranked among the school's all-time leaders in doubles (second with 46), hits (third with 240) and runs (sixth with 147) and was named the 2010 Big Ten Freshman of the Year.

Major League Baseball has suspended 17 players for violating the Minor League drug program this year, including two from the Giants organization.

Danny Wild is an editor for MiLB.com. Follow his MLBlog, Minoring in Twitter. This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.